单项选择题
Questions 11--13 are based on the following talk about prodigies, kids with unusual natural abilities. You now have 15 seconds to read Questions 11--13.
What has been found about children of unusual talent（）
A．Many of them are from middle-class families
B．There are more girls than boys among them
C．They are mostly born by natural childbirth
D．Their parents are usually ambitious and humorous